#include <stdio.h>
#include<unistd.h>
#include<sys/types.h>
#include<stdlib.h>
int main()
{
  pid_t pid;
  printf("Before: pid is %d\n", getpid());
  if ( (pid=fork()) == -1 ) perror("fork()"),exit(1);
  printf("After:pid is %d, fork return %d\n", getpid(), pid);
  sleep(1);
  return 0;
}
